In the northeastern United States, bats have been dying by the thousands, struck down by a strange ailment called "white-nose syndrome." A mysterious, fuzzy white fungus appears on the noses and skin of afflicted hibernating bats, which then often starve to death.
Alan Hicks, a bat specialist with the New York State Department of Environmental Conservation, alerted the world to white-nose syndrome in early 2007 after hearing reports of dead bats in caves near Albany.
Now, researchers have identified the mold they consider a possible cause of the disease, reporting their findings Thursday in the online edition of the journal Science. It's a fragile, unusual form of Geomyces fungi, which usually live in cold places such as Antarctica, says David Blehert, lead author of the study. He's head of diagnostic microbiology at the U.S. Geological Survey's National Wildlife Health Center in Madison, Wis.
Blehert can't say for certain that the fungus is killing the bats. "Fungi usually don't kill otherwise healthy animals all on their own," he explains. He says the infection may make a bat wake up too often during hibernation, so that it burns up its reserves of fat too quickly.
A Fragile Fungus
Blehert's lab got involved in the research about a year ago, after Hicks had collected ailing bats with the syndrome and taken them to Melissa Behr, an animal disease specialist at the New York State Department of Health. She couldn't figure out what the problem was.
Hicks "would bring a bunch of bats, and we would triage them over the course of the evening, and I would wonder where the white stuff had gone," Behr said.
The white material was so fragile that it disappeared at the slightest touch. So she moved her operation closer to the bats: inside two abandoned mines.
"I got so I could grab a little bat, stabilize his little head, grab the fungus and put it on a slide," Behr said.
The slides went under a microscope. Behr took photos and sent them to experts such as Blehert, who said, "The mission of my lab suddenly became: What is this white stuff?"
No one had ever seen a fungus like this one. But Blehert and his colleagues retrieved sections of its genetic code and found that it resembled DNA of other cold-loving fungi. The fungus — found on the noses, ears, wings and skin of the infected bats — flourishes at temperatures between 41 and 50 degrees Fahrenheit.
Seeking Clues To Syndrome's Source
Now that scientists have a sample of the fungus's genetic code, they can test for it in other places. They want to know its source, because that might provide a clue to how the epidemic started. Right now, they think something — maybe a person, maybe an animal — carried a trace of this fungus into Howes Cave in upstate New York, 30 miles west of Albany.
That's where someone first took a picture of a white-nosed bat in February 2006. The following year, Blehert said, bats were found dying in five caves — all within 10 miles of Howes Cave. "And by last winter, it was present at 33 sites, out to a 210-kilometer radius," he said.
Hicks, the bat specialist, went looking for evidence of the ailment again this week — along with reporter Brian Mann of North Country Public Radio — in an abandoned iron mine near Port Henry, a village in northeastern New York.
The bats were just settling in for the winter, squealing softly. Hicks collected a few, dropping them into paper lunch bags after checking for marks of the epidemic. Good news: There was no sign of white fuzz.
But the bats are getting wiped out completely in some caves nearby. "I'll be surprised if some of the sites we visited last year aren't at zero, or very near zero, this winter," he whispered to avoid disturbing the bats.
In two sites that scientists have monitored most closely, 78 percent and 97 percent of the bats have died. Nobody knows where the plague will end.